build errors on macOS with Apple clang version 16.0.0

[ClausKlein]

[2/4] Building CXX object examples/CMakeFiles/beman.inplace_vector.examples.fibonacci.dir/fibonacci.cpp.o
FAILED: examples/CMakeFiles/beman.inplace_vector.examples.fibonacci.dir/fibonacci.cpp.o 
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/c++  -I/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX15.1.sdk -mmacosx-version-min=14.7 -MD -MT examples/CMakeFiles/beman.inplace_vector.examples.fibonacci.dir/fibonacci.cpp.o -MF examples/CMakeFiles/beman.inplace_vector.examples.fibonacci.dir/fibonacci.cpp.o.d -o examples/CMakeFiles/beman.inplace_vector.examples.fibonacci.dir/fibonacci.cpp.o -c /Users/clausklein/Workspace/cpp/beman-project/inplace_vector/examples/fibonacci.cpp
In file included from /Users/clausklein/Workspace/cpp/beman-project/inplace_vector/examples/fibonacci.cpp:5:
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:26:16: warning: nested namespace definition is a C++17 extension; define each namespace separately [-Wc++17-extensions]
   26 | namespace beman::inplace_vector {
      |                ^~~~~~~~~~~~~~~~
      |                 { namespace inplace_vector
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:46:12: warning: alias declarations are a C++11 extension [-Wc++11-extensions]
   46 | using If = typename std::conditional<Condition, TrueType, FalseType>::type;
      |            ^
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:52:5: warning: alias declarations are a C++11 extension [-Wc++11-extensions]
   52 |     If<Capacity <= std::numeric_limits<uint8_t>::max(), uint8_t,
      |     ^
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:55:22: error: a space is required between consecutive right angle brackets (use '> >')
   55 |              uint64_t>>>;
      |                      ^~
      |                      > > 
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:60:21: warning: alias declarations are a C++11 extension [-Wc++11-extensions]
   60 |   using size_type = std::size_t;
      |                     ^
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:61:30: warning: alias declarations are a C++11 extension [-Wc++11-extensions]
   61 |   using internal_size_type = inplace_vector_internal_size_type<Capacity>;
      |                              ^
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:63:3: error: unknown type name 'alignas'
   63 |   alignas(T) unsigned char elems[Capacity * sizeof(T)] = {};
      |   ^
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:63:11: error: declaration of 'T' shadows template parameter
   63 |   alignas(T) unsigned char elems[Capacity * sizeof(T)] = {};
      |           ^
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:58:20: note: template parameter is declared here
   58 | template <typename T, std::size_t Capacity>
      |                    ^
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:63:13: error: expected ';' at end of declaration list
   63 |   alignas(T) unsigned char elems[Capacity * sizeof(T)] = {};
      |             ^
      |             ;
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:64:22: error: function definition does not declare parameters
   64 |   internal_size_type size_{0};
      |                      ^
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:67:3: error: unknown type name 'constexpr'
   67 |   constexpr inplace_vector_destruct_base() = default;
      |   ^
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:67:13: error: constructor cannot have a return type
   67 |   constexpr inplace_vector_destruct_base() = default;
      |             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:71:18: error: expected ';' at end of declaration list
   71 |           &other) noexcept(std::is_nothrow_copy_constructible_v<T>)
      |                  ^
      |                  ;
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:104:21: warning: alias declarations are a C++11 extension [-Wc++11-extensions]
  104 |   using size_type = std::size_t;
      |                     ^
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:105:21: warning: alias declarations are a C++11 extension [-Wc++11-extensions]
  105 |   using reference = T &;
      |                     ^
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:106:20: warning: alias declarations are a C++11 extension [-Wc++11-extensions]
  106 |   using iterator = T *;
      |                    ^
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:107:26: warning: alias declarations are a C++11 extension [-Wc++11-extensions]
  107 |   using const_iterator = const T *;
      |                          ^
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:110:3: error: unknown type name 'constexpr'
  110 |   constexpr inplace_vector_base() = default;
      |   ^
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:110:13: error: constructor cannot have a return type
  110 |   constexpr inplace_vector_base() = default;
      |             ^~~~~~~~~~~~~~~~~~~
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:111:56: error: expected ';' at end of declaration list
  111 |   inplace_vector_base(const inplace_vector_base &other) noexcept(
      |                                                        ^
      |                                                        ;
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:227:16: warning: alias declarations are a C++11 extension [-Wc++11-extensions]
  227 |   using base = inplace_vector_base<T, Capacity>;
      |                ^
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:230:22: warning: alias declarations are a C++11 extension [-Wc++11-extensions]
  230 |   using value_type = T;
      |                      ^
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:231:19: warning: alias declarations are a C++11 extension [-Wc++11-extensions]
  231 |   using pointer = T *;
      |                   ^
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:232:25: warning: alias declarations are a C++11 extension [-Wc++11-extensions]
  232 |   using const_pointer = const T *;
      |                         ^
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:233:21: warning: alias declarations are a C++11 extension [-Wc++11-extensions]
  233 |   using reference = value_type &;
      |                     ^
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:234:27: warning: alias declarations are a C++11 extension [-Wc++11-extensions]
  234 |   using const_reference = const value_type &;
      |                           ^
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:235:21: warning: alias declarations are a C++11 extension [-Wc++11-extensions]
  235 |   using size_type = std::size_t;
      |                     ^
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:236:27: warning: alias declarations are a C++11 extension [-Wc++11-extensions]
  236 |   using difference_type = std::ptrdiff_t;
      |                           ^
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:237:20: warning: alias declarations are a C++11 extension [-Wc++11-extensions]
  237 |   using iterator = pointer;
      |                    ^
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:238:26: warning: alias declarations are a C++11 extension [-Wc++11-extensions]
  238 |   using const_iterator = const_pointer;
      |                          ^
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:239:28: warning: alias declarations are a C++11 extension [-Wc++11-extensions]
  239 |   using reverse_iterator = std::reverse_iterator<iterator>;
      |                            ^
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:240:34: warning: alias declarations are a C++11 extension [-Wc++11-extensions]
  240 |   using const_reverse_iterator = std::reverse_iterator<const_iterator>;
      |                                  ^
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:243:3: error: unknown type name 'constexpr'
  243 |   constexpr inplace_vector() noexcept = default;
      |   ^
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:243:13: error: constructor cannot have a return type
  243 |   constexpr inplace_vector() noexcept = default;
      |             ^~~~~~~~~~~~~~
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:243:29: error: expected ';' at end of declaration list
  243 |   constexpr inplace_vector() noexcept = default;
      |                             ^
      |                             ;
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:244:3: error: unknown type name 'constexpr'
  244 |   constexpr inplace_vector(const inplace_vector &) = default;
      |   ^
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:244:13: error: constructor cannot have a return type
  244 |   constexpr inplace_vector(const inplace_vector &) = default;
      |             ^~~~~~~~~~~~~~
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:245:3: error: unknown type name 'constexpr'
  245 |   constexpr inplace_vector(inplace_vector &&) = default;
      |   ^
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:245:43: warning: rvalue references are a C++11 extension [-Wc++11-extensions]
  245 |   constexpr inplace_vector(inplace_vector &&) = default;
      |                                           ^
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:245:13: error: constructor cannot have a return type
  245 |   constexpr inplace_vector(inplace_vector &&) = default;
      |             ^~~~~~~~~~~~~~
/Users/clausklein/Workspace/cpp/beman-project/inplace_vector/include/beman/inplace_vector/inplace_vector.hpp:246:3: error: unknown type name 'constexpr'
  246 |   constexpr inplace_vector &operator=(const inplace_vector &) = default;
      |   ^
fatal error: too many errors emitted, stopping now [-ferror-limit=]
22 warnings and 20 errors generated.
ninja: build stopped: subcommand failed.
iMac:inplace_vector clausklein$ git diff
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0ef0c38..6fbe57a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -56,12 +56,12 @@ set_target_properties(
     beman.inplace_vector
     PROPERTIES VERIFY_INTERFACE_HEADER_SETS ON
 )
-target_compile_features(
-    beman.inplace_vector
-    INTERFACE
-        "$<$<COMPILE_FEATURES:cxx_std_23>:cxx_std_23>"
-        "$<$<NOT:$<COMPILE_FEATURES:cxx_std_23>>:cxx_std_20>"
-)
+# target_compile_features(
+#     beman.inplace_vector
+#     INTERFACE
+#         "$<$<COMPILE_FEATURES:cxx_std_23>:cxx_std_23>"
+#         "$<$<NOT:$<COMPILE_FEATURES:cxx_std_23>>:cxx_std_20>"
+# )
 
 set(TARGET_PACKAGE_NAME ${PROJECT_NAME}-config)
 set(TARGETS_EXPORT_NAME ${PROJECT_NAME}-targets)
iMac:inplace_vector clausklein$ 

[wusatosi]

This was for the old implementation